He is charged with building and planting an explosive device with an electrical timer in the home of Victoria resident Vanessa Middaugh, 29, who is Tijerina's ex-girlfriend on May 9, 2009.

Tijerina planted the device with the intent to kill Middaugh and their infant son in an effort to avoid making child support payments, according to court documents.

Middaugh testified that after returning home from an out-of-town trip, she and her stepfather, Alfred Pernitza Jr., discovered the device in a spare bedroom. They were trying to figure out a problem with an electrical breaker.

"I figured something had to be plugged in that was overloading it," said Pernitza.

Both testified they found several empty water bottles and Gain laundry detergent bottles that were filled with flammable liquids, later identified as gasoline. One of the bottles was connected to a timer that had been plugged into an electrical socket and set for 11:30 p.m.

Additionally, the two said they found newspaper and charcoal briquettes stuffed underneath a bed in the room.

From the placement of the items, Middaugh said she knew they had been placed there with ill intentions.

"By seeing the stuff inside the house and how close it was to my son's room," she said she knew the intent.

"If it would have went off, it would have been a big explosion," said Pernitza.

Pernitza also said the close proximity of his daughter's house to him and his wife's house potentially put them in danger, too.

During the trial, jurors were shown fingerprints taken from bottles at the home and viewed video showing Tijerina purchasing timers from a Victoria store that were identical to the one found in Middaugh's house.

Jurors also began listening to an audio recording of an interview Victoria County Sheriff's Office investigators conducted with Tijerina.

They are expected to continue listening to the audio when the trial resumes Wednesday morning.

Investigators said Tijerina responded with a "vague stare" when told about photos taken from the video footage in the store.